The present invention relates to a camera such as a television camera and a digital still camera, in particular, to a scanning camera capable of changing a photographing direction.
There have been conventionally known a variety of scanning cameras such as a television camera and a digital still camera capable of changing a photographing direction with a remote control operation. Such a scanning camera is employed as, for example, a wide-area surveillance camera. To cover a wide area, the scanning camera changes the photographing direction vertically (in a tilting operation) and horizontally (in a panning operation). Accordingly, it is possible to reduce the number of cameras to cover a wide surveillance area.
A scanning camera is also used in a video teleconference system in which participants at remote places can talk with each other using a high-speed communication line. The scanning camera can continuously aim at any participant in the conference through optimizing a photographing direction.
In the scanning camera, a movable frame supports an entire body of the scanning camera, and a motor moves the movable frame to change a photographing direction vertically and horizontally. In such a configuration, it is necessary to rotate the entire body vertically and horizontally, thereby increasing a size of the scanning camera.
A scanning camera has been proposed to reduce a size, in which only a minimum element required for shooting a picture, i.e. a section composed of a photo lens and an imaging element, is rotated vertically and horizontally. Japanese Patent Publication (Kokai) No. 09-69976 has disclosed a camera, in which a signal processing board is mounted on a horizontally rotatable platform. An imaging device is mounted on a vertically rotatable support base mounted on the platform to change a photographing direction vertically. The camera can rotate vertically with respect to the signal processing board, and the camera is electrically connected to the signal processing board with a flexible cable to be rotatable.
Japanese Patent Publication (Kokai) No. 2002-131806 has disclosed another camera, in which only a minimum element required for shooting a picture, i.e. a section composed of a photo lens and an imaging element, is rotated vertically and horizontally. The moving portion has a small size, thereby requiring only a small drive force and low power consumption. The scanning camera itself also becomes smaller. The movable imaging section is electrically connected to a signal processing board with a flexible cable to be rotatable.
In the conventional cameras described above, a flexible cable is used to electrically connect between a moving module and a fixed module. The flexible cable is easily bendable in a planar surface thereof, and exhibits flexibility in some extent. The flexibility may cause a small resistance as a load on a driver for changing the photographing direction of the camera.
In Japanese Patent Publication (Kokai) No. 09-69976, a long flexible cable extends from the imaging device to the signal processing board to minimize an effect of bending resistance thereof. However, a longer cable results in a higher cost and a larger space.
In Japanese Patent Publication (Kokai) No. 2002-131806, a driver rotates the imaging section vertically and horizontally, thereby obtaining a small size. In the camera, a single flexible cable is used for the connection. Thus, the flexible cable is bendable in one of the tilting and panning operations, and is twisted in the other of the tilting and panning operations, thereby applying a load on the driver due to the twisting of the flexible cable. Further, the flexible cable tends to be short, thereby increasing the effect of the bending resistance. When the camera moves in a wider angle, the bending resistance increases. In general, a smaller camera device has a shorter flexible cable, thereby increasing the bending resistance of the flexible cable.
Accordingly, it is an object of the present invention to provide a compact scanning camera with low power consumption and a minimum bending resistance of a flexible cable within a limited space for accommodating the flexible cable.
Further objects and advantages of the invention will be apparent from the following description of the invention.